Roles of Zinc Finger Protein 423 in Proliferation and Invasion of Cholangiocarcinoma through Oxidative Stress

Oxidative Stress and Redox-Dependent Pathways in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary liver tumor that accounts for 2% of all cancer-related deaths worldwide yearly. It can arise from cholangiocytes of biliary tracts, peribiliary glands, and possibly from progenitor cells or even hepatocytes. CCA is characterized by high chemoresistance, aggressiveness, and poor prognosis. Potentially curative surgical therapy is restricted to a small number of patients with early-stage disease (up to 35%). Accumulating evidence indicates that CCA is an oxidative stress-driven carcinoma resulting from chronic inflammation. Oxidative stress, due to enhanced reactive oxygen species (ROS) production and/or decreased antioxidants, has been recently suggested as a key factor in cholangiocyte oncogenesis through gene expression alterations and molecular damage. However, due to different experimental models and conditions, contradictory results regarding oxidative stress in cholangiocarcinoma have been reported. The role of ROS and antioxidants in cancer is controversial due to their context-dependent ability to stimulate tumorigenesis and support cancer cell proliferation or promote cell death. On these bases, the present narrative review is focused on illustrating the role of oxidative stress in cholangiocarcinoma and the main ROS-driven intracellular pathways. Heterogeneous data about antioxidant effects on cancer development are also discussed.

High XB130 expression in renal cell carcinoma is strongly associated with poor prognosis

The aim of this study was to assess the prognostic value of XB130 expression in three major RCC subtypes, and its association with clinical outcomes and adverse clinicopathologic features. A total of 101 nephrectomy samples at Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand, from 2007 to 2017 were included in the study. XB130 immunohistochemistry was performed on slides from a tissue microarray comprised of 71 clear cell RCCs, 23 papillary RCCs, and 7 chromophobe RCCs, and were scored using a Histoscore system on a 0-300 scale. High XB130 expression in clear cell RCC and papillary RCC patients was associated with poor prognosis (log-rank test, P = 0.013, and P = 0.001, respectively). WHO/ISUP grade (P = 0.001) and XB130 high expression (P = 0.019) were found to be independent risk factors for mortality in clear cell RCC using multivariate analysis. The high expression of XB130 in clear cell RCC patients was also associated with high WHO/ISUP grade (P = 0.011), distant metastasis (P = 0.036), TNM stage (P = 0.007), sarcomatoid/rhabdoid differentiation (P = 0.061), and urinary collecting system invasion (P = 0.002). Similarly, high XB130 expression (P = 0.038) was associated with poor prognosis among papillary RCC patients as well as with lymphovascular invasion (P = 0.022), TNM stage (P = 0.030), and sarcomatoid/rhabdoid differentiation (P = 0.044). Overall, our findings showed that high XB130 expression in clear cell RCC and papillary RCC patients are associated with a worse prognosis.

Identification of NIFTP-Specific mRNA Markers for Reliable Molecular Diagnosis of Thyroid Tumors

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a low-risk thyroid tumor with a favorable prognosis. Nonetheless, differentiating NIFTP from other thyroid tumors remains challenging, necessitating reliable diagnostic markers. This study is aimed at discovering NIFTP-specific mRNA markers through RNA sequencing analysis of thyroid tumor tissues. We performed mRNA expression profiling for 74 fresh frozen thyroid tissue samples, including NIFTP and benign and malignant follicular-cell-derived tumors. NIFTP/malignant tumors showed 255 downregulated genes and 737 upregulated genes compared to benign tumors. Venn diagram analysis revealed 19 significantly upregulated and 7 downregulated mRNAs in NIFTP. Akaike information criterion analysis allowed us to select OCLN, ZNF423, LYG1, and AQP5 mRNA markers. We subsequently developed a predictive model based on logistic regression analysis using these four mRNAs, which we validated in independent samples (n = 90) using a qRT-PCR assay. This model demonstrated high accuracy in predicting NIFTP in discovery dataset (AUC (area under the receiver operating characteristic) = 0.960) and the validation dataset (AUC = 0.757). Our results suggest that OCLN, ZNF423, LYG1, and AQP5 mRNA markers might serve as reliable molecular markers for identifying NIFTP among other thyroid tumors, ultimately aiding in accurate diagnosis and management of NIFTP patients.

Guanine nucleotide exchange factor T exerts the cancer-promoting function in cholangiocarcinoma by enhancing the Wnt-GSK-3β-β-catenin cascade via regulation of Rac1/Cdc42

Guanine nucleotide exchange factor T (GEFT), which is frequently overexpressed in cancers, is closely related to tumorigenicity and metastasis. Up to now, little is known about the relationship between GEFT and cholangiocarcinoma (CCA). The work explored the expression and function of GEFT in CCA and revealed the underlying mechanisms. Both CCA clinical tissues and cell lines expressed higher levels of GEFT than normal controls. High GEFT levels were correlated with a low overall survival rate in CCA patients. A decrease in GEFT by RNA interference caused remarkable anticancer effects in CCA cells, including retarded proliferation, delayed cell cycle progression, subdued metastatic potential and enhanced chemosensitivity. Mechanistically, GEFT mediated the Wnt-GSK-3β-β-catenin cascade associated with the regulation of Rac1/Cdc42. The inhibition of Rac1/Cdc42 markedly diminished the enhancing effect of GEFT on the Wnt-GSK-3β-β-catenin and reversed GEFT-mediated cancer-promoting effects in CCA. Moreover, the reactivation of β-catenin diminished GEFT-reduction-induced anticancer effects. Critically, CCA cells with decreasing GEFT had a weakened ability to form xenografts in mouse models. Collectively, this work illustrates that GEFT-mediated Wnt-GSK-3β-β-catenin cascade represents a novel mechanism underlying CCA progression and propose a decrease in GEFT as a potential path for treatment in CCA patients.

Overexpression of Insulin Receptor Substrate 1 (IRS1) Relates to Poor Prognosis and Promotes Proliferation, Stemness, Migration, and Oxidative Stress Resistance in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is one of the oxidative stress-driven carcinogenesis through chronic inflammation. Insulin receptor substrate 1 (IRS1), an adaptor protein of insulin signaling pathways, is associated with the progression of many inflammation-related cancers. This study hypothesized that oxidative stress regulates IRS1 expression and that up-regulation of IRS1 induces CCA progression. The localizations of IRS1 and an oxidative stress marker (8-oxodG) were detected in CCA tissues using immunohistochemistry (IHC). The presence of IRS1 in CCA tissues was confirmed using immortal cholangiocyte cells (MMNK1), a long-term oxidative-stress-induced cell line (ox-MMNK1-L), and five CCA cell lines as cell culture models. IRS1 was overexpressed in tumor cells and this was associated with a shorter patient survival time and an increase in 8-oxodG. IRS1 expression was higher in ox-MMNK1-L cells than in MMNK1 cells. Knockdown of IRS1 by siRNA in two CCA cell lines led to inhibition of proliferation, cell cycle progression, migration, invasion, stemness, and oxidative stress resistance properties. Moreover, a transcriptomics study demonstrated that suppressing IRS1 in the KKU-213B CCA cell line reduced the expression levels of several genes and pathways involved in the cellular functions. The findings indicate that IRS1 is a key molecule in the connection between oxidative stress and CCA progression. Therefore, IRS1 and its related genes can be used as prognostic markers and therapeutic targets for CCA therapy.

Distinct molecular impact patterns of abamectin on Apis mellifera ligustica and Apis cerana cerana

The effects of insecticides on bee health are a topic of intensive research. Although abamectin is toxic to bees, the molecular impact of abamectin needs to be clarified. Here, we found that Apis cerana cerana exhibited a higher mortality rate when exposed to abamectin than Apis mellifera ligustica. In addition, A. cerana cerana had markedly higher numbers of differentially expressed genes (DEGs), differentially expressed proteins (DEPs) and differentially expressed metabolites (DEMs) than A. mellifera ligustica during exposure to abamectin. These results indicate that abamectin exposure exerts stronger effects on A. cerana cerana than on A. mellifera ligustica. In addition, six DEGs, two DEPs and two DEMs overlapped between the two bee species under abamectin exposure; however, some genes or proteins from the zinc finger protein, superoxide dismutase and peroxiredoxin families and the energy metabolism pathway were only unregulated in A. cerana cerana, which indicates a significant difference in the impact of abamectin on the two bee species. Despite these differences, several of the same gene families, such as heat shock proteins, cytochrome P450, odorant-binding proteins and cuticle proteins, and pathways, including the carbohydrate metabolism, immune system, lipid metabolism, amino acid metabolism, sensory system, locomotion and development pathways, were influenced by abamectin exposure in both A. cerana cerana and A. mellifera ligustica. Together, our results indicate that abamectin causes adverse effects on bees and thus poses a risk to bee populations and that abamectin exposure affects A. cerana cerana more strongly than A. mellifera ligustica. These findings improve our understanding of the behavioural and physiological effects of abamectin on bees.

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a group of heterogenous malignancies arising from bile duct epithelium with distinct pathological features. Adaptor proteins have implicated in cell proliferation, migration, and invasion of different cancer cells. The objective of this study was to assess whether the adaptor protein XB130 (AFAP1L2) is a critical biological determinant of CCA outcome. XB130 expression levels were investigated in four CCA cell lines compared to an immortalized cholangiocyte cell line by Western blotting. Small interfering (si) RNA-mediated XB130 gene silencing was conducted to evaluate the effects of reduced XB130 expression on cell proliferation, migration, and invasion by MTT, transwell migration and cell invasion assay. The immunohistochemical quantification of XB130 levels were performed in surgically resected formalin-fixed, paraffin-embedded specimens obtained from 151 CCA patients. The relationship between XB130 expression and the clinicopathological parameters of CCA patients were analyzed. Our results showed that XB130 was highly expressed in KKU-213A cell line. Knockdown of XB130 using siRNA significantly decreased the proliferation, migration, and invasion properties of KKU-213A cells through the inhibition of PI3K/Akt pathway, suggesting that XB130 plays an important role in CCA progression. Moreover, elevated XB130 expression levels were positive relationship with lymphovascular space invasion (LVSI), intrahepatic type of CCA, high TNM staging (stage III, IV), high T classification (T3, T4), and lymph node metastasis. We provide the first evidence that the overexpression of XB130 is associated with tumorigenic properties of CCA cells, leading to CCA progression with aggressive clinical outcomes.

In silico prediction of secretory proteins of Opisthorchis viverrini, Clonorchis sinensis and Fasciola hepatica that target the host cell nucleus

Liver flukes Fasciola hepatica, Opisthorchis viverrini and Clonorchis sinensis are causing agents of liver and hepatobiliary diseases. A remarkable difference between such worms is the fact that O. viverrini and C. sinensis are carcinogenic organisms whereas F. hepatica is not carcinogenic. The release of secretory factors by carcinogenic flukes seems to contribute to cancer development however if some of these target the host cell nuclei is unknown. We investigated the existence of O. viverrini and C. sinensis secretory proteins that target the nucleus of host cells and compared these with the corresponding proteins predicted in F. hepatica. Here we applied an algorithm composed by in silico approaches that screened and analyzed the potential genes predicted from genomes of liver flukes. We found 31 and 22 secretory proteins that target the nucleus of host cells in O. viverrini and C. sinensis, respectively, and that have no homologs in F. hepatica. These polypeptides have enriched the transcription initiation process and nucleic acid binding in O. viverrini and C. sinensis, respectively. In addition, other 11 secretory proteins of O. viverrini and C. sinensis, that target the nucleus of host cells, had F. hepatica homologs, have enriched RNA processing function. In conclusion, O. viverrini and C. sinensis have 31 and 22 genes, respectively, that may be involved in their carcinogenic action through a direct targeting on the host cell nuclei.

Promoter hypermethylation of early B cell factor 1 (EBF1) is associated with cholangiocarcinoma progression

DNA hypermethylation in a promoter region causes gene silencing via epigenetic changes. We have previously reported that early B cell factor 1 (EBF1) was down-regulated in cholangiocarcinoma (CCA) tissues and related to tumor progression. Thus, we hypothesized that the DNA hypermethylation of EBF1 promoter would suppress EBF1 expression in CCA and induce its progression. In this study, the DNA methylation status of EBF1 and mRNA expression levels were analyzed in CCA and normal bile duct (NBD) tissues using a publicly available database of genome-wide association data. The results showed that the DNA methylation of EBF1 promoter region was significantly increased in CCA tissues compared with those of NBD. The degree of methylation was negatively correlated with EBF1 mRNA expression levels. Using methylation-specific PCR technique, the DNA methylation rates of EBF1 promoter region were investigated in CCA tissues (n=72). CCA patients with high methylation rates of EBF1 promoter region in the tumor tissues (54/72) had a poor prognosis. Higher methylation rates of EBF1 promoter region have shown in all CCA cell lines than that of an immortal cholangiocyte cell line (MMNK1). Upon treatment with the DNA methyltransferase inhibitor 5-Aza-dC, increased EBF1 expression levels and reduced DNA methylation rates were observed in CCA cells. Moreover, restoration of EBF1 expression in CCA cells led to inhibition of cell growth, migration and invasion. In addition, RNA sequencing analysis suggested that EBF1 is involved in suppression of numerous pathways in cancer. Taken together, DNA hypermethylation in the EBF1 promoter region suppresses EBF1 expression and induces CCA progression with aggressive clinical outcomes.

BCAT1 binds the RNA-binding protein ZNF423 to activate autophagy via the IRE1-XBP-1-RIDD axis in hypoxic PASMCs

Abnormal functional changes in pulmonary artery smooth muscle cells are the main causes of many lung diseases. Among, autophagy plays a crucial role. However, the specific molecular regulatory mechanism of autophagy in PASMCs remains unclear. Here, we first demonstrate that BCAT1 played a key role in the autophagy of hypoxic PASMCs and hypoxic model rats. BCAT1-induced activation and accumulation of the autophagy signaling proteins BECN1 and Atg5 by the endoplasmic reticulum (ER) stress pathway. Interestingly, we discovered that BCAT1 bound IRE1 on the ER to activate expression of its downstream pathway XBP-1-RIDD axis to activate autophagy. More importantly, we identified an RNA-binding protein, zinc finger protein 423, which promoted autophagy by binding adenylate/uridylate (AU)-rich elements in the BCAT1 mRNA 3′-untranslated region. Overall, our results identify BCAT1 as a potential therapeutic target for the clinical treatment of lung diseases and reveal a novel posttranscriptional regulatory mechanism and signaling pathway in hypoxia-induced PASMC autophagy.